In a method of coding a video, a motion vector and a reference picture index of a coding target block may be determined using a motion vector and a reference picture index of a neighboring block in conventional P_SKIP and B_SKIP modes.
However, when the motion vector or the reference picture index of the neighboring block does not exist, the P_SKIP or the B_SKIP mode may be performed using a motion vector (0, 0) or a reference picture index of ‘0’.
Consequently, this scheme does not properly use local characteristics adjacent to the coding target block.
In general, there exists a high correlation between the coding target block and the neighboring block thereof. A context model may be widely reflected in an video coding standard to be used based on an assumption with respect to the correlation.
The video coding standard may support an intra-coding in a inter slice. In a specific environment, there is a case in which an importance of an intra-coded macro block (MB) within the inter slice may be much greater than that of an inter-coded macro block.